<title>最优布线问题</title><link href="http://hzoi.com/tomorrow.css" rel="stylesheet"><div class="ui existing segment"><pre><code><span class="pl-cp">#include</span><span class="pl-cpf">&lt;bits/stdc++.h&gt;</span><span class="pl-cp"></span>
<span class="pl-k">using</span> <span class="pl-k">namespace</span> <span class="pl-n">std</span><span class="pl-p">;</span>
<span class="pl-k">const</span> <span class="pl-kt">int</span> <span class="pl-n">inf</span><span class="pl-o">=</span><span class="pl-mh">0x3f3f3f3f</span><span class="pl-p">;</span>
<span class="pl-kt">int</span> <span class="pl-n">mapp</span><span class="pl-p">[</span><span class="pl-mi">150</span><span class="pl-p">][</span><span class="pl-mi">150</span><span class="pl-p">];</span>
<span class="pl-kt">int</span> <span class="pl-n">dis</span><span class="pl-p">[</span><span class="pl-mi">150</span><span class="pl-p">];</span>
<span class="pl-kt">int</span> <span class="pl-n">vis</span><span class="pl-p">[</span><span class="pl-mi">150</span><span class="pl-p">];</span>
<span class="pl-kt">int</span> <span class="pl-n">n</span><span class="pl-p">;</span>
 
<span class="pl-kt">void</span> <span class="pl-nf">prim</span><span class="pl-p">()</span>
<span class="pl-p">{</span>
    <span class="pl-kt">int</span> <span class="pl-n">sum</span><span class="pl-o">=</span><span class="pl-mi">0</span><span class="pl-p">;</span>
    <span class="pl-n">memset</span><span class="pl-p">(</span><span class="pl-n">vis</span><span class="pl-p">,</span><span class="pl-mi">0</span><span class="pl-p">,</span><span class="pl-k">sizeof</span><span class="pl-p">(</span><span class="pl-n">vis</span><span class="pl-p">));</span>
    <span class="pl-k">for</span><span class="pl-p">(</span><span class="pl-kt">int</span> <span class="pl-n">i</span><span class="pl-o">=</span><span class="pl-mi">1</span><span class="pl-p">;</span><span class="pl-n">i</span><span class="pl-o">&lt;=</span><span class="pl-n">n</span><span class="pl-p">;</span><span class="pl-n">i</span><span class="pl-o">++</span><span class="pl-p">)</span> <span class="pl-n">dis</span><span class="pl-p">[</span><span class="pl-n">i</span><span class="pl-p">]</span><span class="pl-o">=</span><span class="pl-n">mapp</span><span class="pl-p">[</span><span class="pl-mi">1</span><span class="pl-p">][</span><span class="pl-n">i</span><span class="pl-p">];</span>
    <span class="pl-n">vis</span><span class="pl-p">[</span><span class="pl-mi">1</span><span class="pl-p">]</span><span class="pl-o">=</span><span class="pl-mi">1</span><span class="pl-p">;</span>
    <span class="pl-n">dis</span><span class="pl-p">[</span><span class="pl-mi">1</span><span class="pl-p">]</span><span class="pl-o">=</span><span class="pl-mi">1</span><span class="pl-p">;</span>
    <span class="pl-k">for</span><span class="pl-p">(</span><span class="pl-kt">int</span> <span class="pl-n">i</span><span class="pl-o">=</span><span class="pl-mi">1</span><span class="pl-p">;</span><span class="pl-n">i</span><span class="pl-o">&lt;=</span><span class="pl-n">n</span><span class="pl-o">-</span><span class="pl-mi">1</span><span class="pl-p">;</span><span class="pl-n">i</span><span class="pl-o">++</span><span class="pl-p">){</span>
        <span class="pl-kt">int</span> <span class="pl-n">minn</span><span class="pl-o">=</span><span class="pl-n">inf</span><span class="pl-p">;</span>
        <span class="pl-kt">int</span> <span class="pl-n">u</span><span class="pl-p">;</span>
        <span class="pl-k">for</span><span class="pl-p">(</span><span class="pl-kt">int</span> <span class="pl-n">j</span><span class="pl-o">=</span><span class="pl-mi">1</span><span class="pl-p">;</span><span class="pl-n">j</span><span class="pl-o">&lt;=</span><span class="pl-n">n</span><span class="pl-p">;</span><span class="pl-n">j</span><span class="pl-o">++</span><span class="pl-p">){</span>
            <span class="pl-k">if</span><span class="pl-p">(</span><span class="pl-o">!</span><span class="pl-n">vis</span><span class="pl-p">[</span><span class="pl-n">j</span><span class="pl-p">]</span><span class="pl-o">&amp;&amp;</span><span class="pl-n">minn</span><span class="pl-o">&gt;</span><span class="pl-n">dis</span><span class="pl-p">[</span><span class="pl-n">j</span><span class="pl-p">]){</span>
                <span class="pl-n">u</span><span class="pl-o">=</span><span class="pl-n">j</span><span class="pl-p">;</span>
                <span class="pl-n">minn</span><span class="pl-o">=</span><span class="pl-n">dis</span><span class="pl-p">[</span><span class="pl-n">j</span><span class="pl-p">];</span>
            <span class="pl-p">}</span>
        <span class="pl-p">}</span>
        <span class="pl-n">vis</span><span class="pl-p">[</span><span class="pl-n">u</span><span class="pl-p">]</span><span class="pl-o">=</span><span class="pl-mi">1</span><span class="pl-p">;</span>
        <span class="pl-n">sum</span><span class="pl-o">+=</span><span class="pl-n">minn</span><span class="pl-p">;</span>
        <span class="pl-k">for</span><span class="pl-p">(</span><span class="pl-kt">int</span> <span class="pl-n">j</span><span class="pl-o">=</span><span class="pl-mi">1</span><span class="pl-p">;</span><span class="pl-n">j</span><span class="pl-o">&lt;=</span><span class="pl-n">n</span><span class="pl-p">;</span><span class="pl-n">j</span><span class="pl-o">++</span><span class="pl-p">){</span>
            <span class="pl-k">if</span><span class="pl-p">(</span><span class="pl-o">!</span><span class="pl-n">vis</span><span class="pl-p">[</span><span class="pl-n">j</span><span class="pl-p">]</span><span class="pl-o">&amp;&amp;</span><span class="pl-n">mapp</span><span class="pl-p">[</span><span class="pl-n">u</span><span class="pl-p">][</span><span class="pl-n">j</span><span class="pl-p">]</span><span class="pl-o">&lt;</span><span class="pl-n">dis</span><span class="pl-p">[</span><span class="pl-n">j</span><span class="pl-p">]){</span>
                <span class="pl-n">dis</span><span class="pl-p">[</span><span class="pl-n">j</span><span class="pl-p">]</span><span class="pl-o">=</span><span class="pl-n">mapp</span><span class="pl-p">[</span><span class="pl-n">u</span><span class="pl-p">][</span><span class="pl-n">j</span><span class="pl-p">];</span>
            <span class="pl-p">}</span>
        <span class="pl-p">}</span>
 
    <span class="pl-p">}</span>
    <span class="pl-n">cout</span><span class="pl-o">&lt;&lt;</span><span class="pl-n">sum</span><span class="pl-o">&lt;&lt;</span><span class="pl-n">endl</span><span class="pl-p">;</span>
<span class="pl-p">}</span>
<span class="pl-kt">int</span> <span class="pl-nf">main</span><span class="pl-p">()</span>
<span class="pl-p">{</span>
    <span class="pl-n">ios</span><span class="pl-o">::</span><span class="pl-n">sync_with_stdio</span><span class="pl-p">(</span><span class="pl-nb">false</span><span class="pl-p">);</span>
    <span class="pl-n">cin</span><span class="pl-o">&gt;&gt;</span><span class="pl-n">n</span><span class="pl-p">;</span>
 
    <span class="pl-k">for</span><span class="pl-p">(</span><span class="pl-kt">int</span> <span class="pl-n">i</span><span class="pl-o">=</span><span class="pl-mi">1</span><span class="pl-p">;</span><span class="pl-n">i</span><span class="pl-o">&lt;=</span><span class="pl-n">n</span><span class="pl-p">;</span><span class="pl-n">i</span><span class="pl-o">++</span><span class="pl-p">){</span>
        <span class="pl-k">for</span><span class="pl-p">(</span><span class="pl-kt">int</span> <span class="pl-n">j</span><span class="pl-o">=</span><span class="pl-mi">1</span><span class="pl-p">;</span><span class="pl-n">j</span><span class="pl-o">&lt;=</span><span class="pl-n">n</span><span class="pl-p">;</span><span class="pl-n">j</span><span class="pl-o">++</span><span class="pl-p">){</span>
            <span class="pl-n">cin</span><span class="pl-o">&gt;&gt;</span><span class="pl-n">mapp</span><span class="pl-p">[</span><span class="pl-n">i</span><span class="pl-p">][</span><span class="pl-n">j</span><span class="pl-p">];</span>
        <span class="pl-p">}</span>
    <span class="pl-p">}</span>
    <span class="pl-n">prim</span><span class="pl-p">();</span>
 
    <span class="pl-k">return</span> <span class="pl-mi">0</span><span class="pl-p">;</span>
<span class="pl-p">}</span>
</cpde></pre></div>